[CQ] Riso: Blank vertical lines in masters; burnt out thermal head?

[steadythighs]

Hi there. I recently purchased an RZ990 and am having trouble with faded vertical sections showing up in the prints [photo of problem attached below].

It shows up in the same place across all 3 colour drums, in both digital and scanned data, as well as in the checkerboard test print as seen here, so I assume it's a problem with the thermal head or something similar. I have tried clean the head already...

Am I looking at having to replace the thermal head or does anyone have any suggestions? Thank you

riso-test.jpg

[Iowatech]

Re: Riso: Blank vertical lines in masters; burnt out thermal head?

One thing I can tell you for sure is that blank area isn't being produced by the thermal head. Bad elements in the thermal head produce sharply defined totally blank lines.
A lack of ink on the inside of the drum shell produced that print defect. Hopefully, as you just got the machine you just didn't know that you need to make at least twenty prints per master. If that is the case, once you start running the machine properly the problem will fix itself. Also, there is an "Idling" button on the left hand side of the control panel, you might try pressing that before you run your first batch of prints if the machine has been sitting idle for a while.
I don't mean any disrespect. It's just that the alternative is a lot less desirable, and I'd prefer to see that people who don't get paid to get Riso ink on their hands and clothes get a chance to avoid that.

[steadythighs]

Re: Riso: Blank vertical lines in masters; burnt out thermal head?

Thanks for the response Iowatech. I have run a few hundred prints already, but you are correct that it's not the thermal head. I just tried removing and flipping the pressure roller and the effect was flipped to the other side of the print, so it seems to be a problem of a flat spot on the pressure roller.

[Iowatech]

Re: Riso: Blank vertical lines in masters; burnt out thermal head?

Thanks for the response Iowatech. I have run a few hundred prints already, but you are correct that it's not the thermal head. I just tried removing and flipping the pressure roller and the effect was flipped to the other side of the print, so it seems to be a problem of a flat spot on the pressure roller.

Well, it does sound like the pressure roller should be changed. If you do that, let us know how that turns out, please.

[steadythighs]

Re: Riso: Blank vertical lines in masters; burnt out thermal head?

Sorry for the delay in response. Just wanted to say thank you for the input and confirm that it was indeed the pressure roller. Got it changed out for a new one and everything is running smoothly now.